Theodor burmeister



(No Model.)

T. BURMEISTER.

FURNACE.

No. 538,726. Patented May 7, 1895.

Warm:

ATENT p tCE.

THEODOR BURMEISTER, OF RIGA, RUSSIA.

FURNACE.

SPECIFICATION formingpart of Letters Patent No. 538,726, dated May 7, 1895. Application r1611 November 17,1894. Serial No. 529,168. (No model.)

To 00% whom it may concern.-

Be it known thatLTHEoDoR BURMEISTER, a subject of the Russian Emperor, and a resident of Riga, in the Province of Livonia, Empire of Russia, have invented an Improved Furnace, of which the following is an exact specification.

This invention relates to a furnace, in which a tripartite grate consisting of a horizontal front-grate, an inclined middle-grate and a horizontal rear-grate is combined with a vault covering the front grate and terminating in a frontal arch above the middle portion ofthe inclined grate. The latter is-of a special construction, and the purpose of the whole is to obtain a perfect combustion with but a slight chimney-draft, as will all be more fully described hereinafter.

In order to make my invention more clear, I refer to the accompanying drawings, in which similar letters denote similar parts throughout the different views, and in which- Figure 1 is a vertical longitudinal section through my improved furnace, showing the same combined with a tubular boiler. Fig. 2 is a vertical longitudinal section through the inclined middle grate, drawn on a larger scale than that of Fig. 1; and Fig. 3 is a vertical cross-section through two bars of the middle grate, drawn on a larger scale than that of Fig. 2.

The inclined grate b, Fig. 1, which is arranged between the front-gratea and the reargrate c is composed of bars of special construction, as represented in Figs. 2 and 3. Each of these grate-bars consists of a thick-walled pipefand a bar proper g, the lower portion of which latter is grooved so as to correspond to the shape of the pipe. Both parts are connected with each other by hoops or bows n. All the said pipes f terminate at their lower ends into a hollow bearing-bar e, the channel of which is connected with a water-conduit, a reservoir or the like, so that the pipes are filled with water up to their tops. The pipes f are provided at their tops with small holes (indicated in Figs. 2 and 3) letting the water escape out of the pipes into the numerous small spaces and grooves existing between the neighboring surfaces of the pipes f and the bars 9. That water, on flowing downward (partly on account of adhesion, partly on account of gravity) between the said surfaces, is heated, and turned into steam. The latter escaping at the two sides of each bar enters the glowing coke lying on grate 6,.and is decomposed thereby. The products of the decomposition mix with the gases coming from the front-grate, and the combustion of those gases is greatly promoted thereby.

The vault d, which covers the front-grate wholly and the middle grate but half, is somewhat inclined toward the latter and terminates in a frontal arch 01'. Therefore, the gases that are evolved by the fuel of the frontgrate, and are mixed there with air, are caused to approach the glowing fuel of the middlegrate; and the air, while cooling the vault, is heated to a high degree. The combustible gases therefore, are nearly perfectly burned, and the remainder of them is burned together with the product of decomposition of the steam, as above explained. The access of air is regulated by the front-slide h.

- In feeding the furnace, the glowing coal of the front-grate is shoved from the latter down upon the top-portion of the middle grate, from where a part of the coal glides downward according to the progressing combustion. The slag and other incombustible components arrive finally on the slag-grate c, and are removed from the latter through a door 0'. After the front-grate has been fed with fresh coal, part of the glowing coal, that has been shoved forward upon the top-edge of the inclined grate, is drawn backward, and distributed over the layer of the fresh coal, so that the gases evolved by the latter are compelled to flow through the said glowing coal.

The improved furnace offers the advantage, that with but a slight excess of air a perfect combustion of the fuel may be attained, without requiring for such a result a particularly clever stoker. The maintenance of the necessary high temperature is done by the second grate (the inclined middle grate) and the frontal arch of the vault, the latter at the same time preventing the boiler from being cooled by the fresh air. The stoker is less exposed to the heat, than is the case with a plane-grate and step-grate, and the slacking off need be made more seldom and requires less time than with any other grate.

The draft of the chimney need be but slight,

which is of importance for the use of my improved furnace for tubular boilers, in that the useful effect of the latter is greatly impaired, it much air is sucked behind the firebridge into the lines. The construction of my improved furnace is such that the latter may easily be substituted for an existing plan t.

Having now particularly described the nature of this invention, what I desire to secure by Letters Patent of the United States is- 1. In a furnace, the combination with a front-grate, and a lower rear-grate, of an inclined middle-grate the bars of which are provided with Water-channels having apertures adapted to let the water escape, for the pur pose as described.

2. In a furnace, the combination with a front-grate, and a lower rear-grate, of an inclined middle-grate the bars of which are provided with channels adapted to lead water from the lower end to the top-end of said bars, said channels having apertures adapted to let the water escape at the top of said inclined grate, for the purpose as described.

3. In a furnace, the combination with a front-grate, and with a lower rear-grate, of an inclined middle-grate the bars of which are composed of pipes, and of bars proper connected with said pipes, the latter having apertures adapted to let the water escape; a vault covering the said front-grate as well as part of the said inclined grate, said vault terminating in a frontal arch, for the purpose as described.

In testimony whereof I have signed this specification in the presence of two subscribing witnesses.

THEODOR BURMEISTER.

Witnesses:

A. KUHNT, H. P. VITH. 

